from The Open University
Alternatively you can skip the navigation by pressing 'Enter'.
Life In Cold Blood: Sophisticated SerpentsSunday, 30th August 2015 08:00 - YesterdayThey get a bad rap in the Bible, but snakes are really quite wonderful Read more: Life In Cold Blood: Sophisticated Serpents
Life In Cold Blood: Sophisticated SerpentsSunday, 30th August 2015 13:00 - Yesterday
The world’s busiest railway 2015 – Mumbai Railway: Episode 1Sunday, 30th August 2015 18:00 - BBC Two
More or Less: Chinese market crash, e-cigarettes and runnersSunday, 30th August 2015 20:00 - BBC Radio 4
More or Less: Chinese market crash, e-cigarettes and runnersAvailable until Sunday, 27th September 2015 16:55More or Less investigates the Chinese market crash, e-cigarettes, engineering and how sprinters run so fast. Read more: More or Less: Chinese market crash, e-cigarettes and runners
The world’s busiest railway 2015 – Mumbai Railway: Episode 1Available until Tuesday, 29th September 2015 19:00
Are our kids tough enough? Chinese school: Episode TwoAvailable until Monday, 28th September 2015 01:55
Canals: The Making of a Nation: The Boat PeopleAvailable until Sunday, 27th September 2015 20:00
OpenLearn Live: August Bank Holiday Special 2015Not so much live, but with a great collection of free courses, things to watch and listen to, and... Read more: OpenLearn Live: August Bank Holiday Special 2015
Are our kids tough enough? Chinese schoolIn a unique experiment, five teachers from China take over the education of 50 teenagers in a... Read more: Are our kids tough enough? Chinese school
Challenges in advanced management accountingThis free course, Challenges in advanced management accounting, focuses on strategic management... Try: Challenges in advanced management accounting now
Forensic psychologyDiscover how psychology can help obtain evidence from eyewitnesses in police investigations and... Try: Forensic psychology now
Energy resources: Solar energy
Energy from sources other than fossil and nuclear fuels is to a large extent free of...
Energy from sources other than fossil and nuclear fuels is to a large extent free of the concerns about environmental effects and renewability that characterize those two sources. Each alternative source supplies energy continuall, whether or not we use it, and most have their origins in energy generated outside the Earth, yet the potential of each is limited by its total supply set against its rate of use. The Sun will radiate energy until it ceases thermonuclear fusion, in around 5 billion years. This unit explores the Sun as a potential source of usable energy.
By the end of this unit you should be able to:
- explain the principles that underlie the ability of various natural phenomena to deliver solar energy;
- outline the technologies that are used to harness the power of solar energy;
- discuss the positive and negative aspects of solar energy in relation to natural and human aspects of the environment.
Study this free course
Enrol to access the full course, get recognition for the skills you learn and track your progress. Make your learning visible!
Energy resources: Solar energy
Energy from sources other than fossil or nuclear fuels is to a large extent free of the concerns about environmental effects and renewability that characterise those two sources. Each alternative source supplies energy continually, whether or not we use it. Many alternative sources of energy have been used in simple ways for millennia, e.g. wind and water mills, sails, wood burning – but only in the last two centuries has their potential begun to be exploited on an industrial scale. Except for geothermal energy, all have their origins in energy generated outside the Earth, yet the potential of each is limited by its total supply set against its rate of use. Each is likely to be renewable in the sense that the available rates of supply of each exceed those at which they are used. The main concern is whether or not such alternatives can supplant fossil- and nuclear-fuel use to power social needs fast enough to avoid the likelihood of future global warming and other kinds of pollution.
One of the alternative sources to consider is solar energy.
The Sun will radiate energy until it ceases thermonuclear fusion, in around 5 billing years. About 33% of the solar power that enters the Earth's system heats the atmosphere and contributes to setting winds and waves in motion. Of that reaching the Earth's surface, 70% falls on the sea, setting in motion ocean currents and a large proportion of the circulation of water vapour in the atmosphere because of evaporation from the ocean surface. The remainder falls on the land. Solar energy is redistributed through interlinked surface systems:
- the carbon cycle based on photosynthesis;
- atmospheric circulation and the water cycle;
- winds and ocean waves; and the ocean current system.
Each of them is a potential source of useable energy. In every case, with the exception of the energy available from surface water flow, humanity comes nowhere near exploiting the Sun's potential to supply useable energy; in fact, we really do not know the practical limits. Whatever those are, they will not disappear as a resource – all are renewable. Compare this with the solar energy stored chemically by the degraded products of photosynthesis in fossil fuels. Although carbon burial adds continually to that resource, its pace of renewal (between 1 to 10 GW – Figure 1) is about 2000 times slower than we use it. Fossil fuels are non-renewable and declining extremely quickly in terms of human history.
This unit explores Solar power as a source of directly useable energy.
This unit is from our archive and is an adapted extract from Earth's physical resources: origin, use and environmental impact (S278) which is no longer taught by The Open University. If you want to study formally with us, you may wish to explore other courses we offer in.
This is an extract from an Open University course which is no longer available to new students. If you found this interesting you could explore more free Environmental Science courses or view the range of currently available OU Environmental Science courses.
Copyright & revisions
Originally published: Wednesday, 20th July 2011
- Creative-Commons: The Open University is proud to release this free course under a Creative Commons licence. However, any third-party materials featured within it are used with permission and are not ours to give away. These materials are not subject to the Creative Commons licence. See terms and conditions. Full details can be found in the Acknowledgements section.
- This site has Copy Reuse Tracking enabled - see our FAQs for more information.
If you enjoyed this, why not follow a feed to find out when we have new things like it? Choose an RSS feed from the list below. (Don't know what to do with RSS feeds?)
Remember, you can also make your own, personal feed by combining tags from around OpenLearn.